The invention relates to an arrangement for controlling the quantity and period of controllable charging of pitch coke furnaces whose pitch supply conduits are connected to a heatable ring circuit and are in connection with at least one pitch reservoir via this ring circuit.
Into pitch coke furnaces there are poured liquid pitches having a softening point according to Kramer-Sarnow (SKS) of about 150.degree. C. These pitches have such a viscosity that they are difficult to convey, tending to foam and to solidify immediately upon cooling, so that pumps and pipelines for distributing the pitch have to be appropriately adapted to these circumstances. In particular, pitch supply conduits have to be laid in such a manner that they can be flushed with overheated steam at certain time intervals in order to prevent obstructions.
The pouring or charging of pitch into the pitch coke furnaces has to be effected in accurately measured amounts and over certain periods of time, since otherwise a too intense degassing and foam formation would occur within the furnace, thus leading to what is called "pressing" of the furnaces. In case of a pressing of the furnace, pitch will penetrate both into the gas take-off main and out of the filling pipes and doors. At the same time, this procedure also involves the formation of pitch vapors which results in considerable difficulties, i.e. operational disturbances as well as negative effects on the environment and on health.
Owing to the tendency of the pitches to foam, the necessary accuracy is not achieved with the quantitative measurements carried out previously by means of floats or filling level measuring means using radioactive preparations. Also, known flow meters are not suitable for this purpose.